The present invention relates to a punch press which adopts a turret, a cartridge or the like as a tool supporting body, and specifically to a punch press of three tracks type wherein three punch tools are arranged in a diameter direction of the turret, or in the direction orthogonal to the direction in which the cartridge advances.
In the conventional turret punch press of three tracks type, a striker of a ram is transferred to a diameter direction of a turret, one punch tool of the three tracks is selected, and then a punching is carried out. For a means for transferring the striker of the ram in the diameter direction of the turret, a means adopting a cylinder device of two stage stroke wherein two pistons are arrange in series within the cylinder is publicly known (for example, the Japanese Patent Publication (Tokkou-Shou) No. 52-27393).
However, in the means adopting the cylinder device of two stage stroke, since the cylinder device is unique, it leads to the increase in the cost. In addition, since the cylinder device that is long in the diameter direction of the turret is necessary to be supported to the ram which carries out the punch operation, there is also a problem in the strength. In the punch press of the three tracks cartridge type, there are also similar problems.
The object of the present invention is to provide a punch press that is capable of selecting a punch tool of three tracks by using a general single stroke cylinder device, and obtaining sufficient supporting strength of the cylinder device.
The punch press of the present invention comprises a tool supporting body provided with a plurality of punch tools, and a ram for hitting the punch tool of the tool supporting body. The tool supporting body comprises three tracks of tool arrangement with an interval between each one. The ram comprises a ram main body which is capable of elevating and descending, a striker which is provided transferable in a direction separating from the three tracks at a lower part of the ram main body, a link member which is connected rotatable in both directions to the striker at the middle of a length direction, two cylinder devices wherein piston rods are connected rotatable to both ends of the link member, and a striker position control means for positioning the striker to the position corresponding to the three tracks by the combination of an advancing position and a receding position of the piston of both cylinder devices.
According to this structure, since two cylinder devices are connected to the link member that is rotatable in both directions and connected to the striker in the middle, by the combination of the advancing position and the receding position of these two cylinder devices, the position of the striker can be fixed to the position corresponding to three tracks. Therefore, for the cylinder device, a special and expensive device like the two stage stroke is not necessary, and the general cylinder device can be used. As a result, even when using two cylinder devices, the cost can be suppressed. Moreover, since the two cylinder devices can be provided to the ram main body individually, a supporting strength of the cylinder device to the ram main body and be obtained sufficiently.
Further, each of the three tracks in the tool supporting body is not necessarily required to be provided with a plurality of punch tools within the same track, and at least one punch tool is to be provided within the track.
In the present invention, the tool supporting member can be a turret. In the case the tool supporting member is the turret, the punch press of the present invention comprises a turret which includes a plurality of punch tools in the periphery direction and is a tool supporting body rotatable around the center of the periphery, and a ram which is provided capable of elevating and descending at a fixed position to the turret and hits the punch tool determined by the rotation of the turret. The turret is provided with three tracks of tool arrangement which differ in the diameter direction position. The ram comprises a ram main body which is capable of elevating and descending, a striker which is provided transferable in the direction separating from the three tracks at the lower part of the ram main body, a link member which is connected rotatable in both directions to the striker at the middle of the length direction, two cylinder devices of which the piston rods are connected rotatable to both ends of the link member, and a striker position control means for positioning the striker to the position corresponding to the three tracks by the combination of the advancing position and the receding position of the piston of both cylinder devices. The direction separating from the tracks is, for example, a diameter direction of the turret.
Further, each of the three tracks in the turret is not necessarily required to be provided with a plurality of punch tools within the same track, and at least one punch tool is to be provided within the track. For example, a tool setting station comprising the punch tool at the turret can be provided in a plurality in the periphery direction, and three punch tools can be arranged separating to the diameter direction of the turret within at least one tool setting station.
Both cylinder devices are provided so that the transferring direction of the piston rod is to be the direction separating from the three tracks, and the piston and the link member can be connected so that the transferring direction of the piston rod can be maintained. In the case of this structure, the swing of the cylinder main body of the cylinder device is not necessary, and since the operating section is small, the decrease in the support strength can be prevented.
Moreover, the cylinder device can be capable of switching the two positions of the advancing end and the receding end of the piston. Under the state in which both pistons are located at the advancing end or at the receding end, the striker can be located at a position corresponding to any one of the tracks among the three tracks, excluding the middle track. In addition, under the state in which one piston is located at the advancing end and the other piston is located at the receding end, the striker can be located at the position corresponding to the middle track. Under such structure, since it is not necessary to stop the piston of the cylinder device at the middle position, the control of the cylinder device is easy, and the switching control of the striker position can be carried out easily.